Improvement in liquids for heating by means of pipes



UNITED STATES PATENT OFFICE.

LOUIS GRIMM AND J OHANNES GORVIN, OF MAGDEBURG, PRUSSIA.

IMPROVEMENT IN LIQUIDS FOR HEATING BY MEANS OF PIPES, &c.

Specification forming part of Letters Patent No. 1 38,082, dated April22, 1873; application filed March 14, 1873.

To all whom it may concern:

Be it known that we, LOUIS GRIMM and JOHANNES CORVIN, both of the cityof Magdeburg, in the Kingdom of Prussia, Germany, have invented a newand Improved Fluid for Filling Heaters and Heating-Pipes, &c., of whichthe following is a specification:

Among the different fluids hitherto used as conductors of heat inheaters and pipes there are none which do not present essentialobjections. Water has been most generally used for that purpose, and themanner of employing the same consists of three different methods. Theolder method, the hot-water or lowpressure heating, presents thefollowing objections: First, great expense in the first arrangement,together with the considerable room required; second, the greatconsumption of fuel third, the considerable loss of time from the timeof starting the fire, because a great quantity of water must be heatednearly to the boiling-point before it begins to circulate and transmitheat into the rooms; fourth, great expense for heating and cleaning theheater and pipes; fifth, the danger of freezing of the pipes when invery cold weather the heating is not constantly continued; sixth, thetemperature of Water cannot be raised above 63 centigrade, inconsequence of which the apparatus will prove insufficient in very coldweather. In consequence of the evaporation and the rather frequentrestoration of water being required, there will be a rapidlyincreasingsediment of mud and incrustation in the pipes, particularly when thewater is limy or impure, which will in a short time render the apparatususeless and dangerous. When the heating apparatus and pipes, 850., arefilled with the fluid below described, there will be no evaporation,and, consequently, no 7 restoring of fluid required; lessfuel will beused; a sediment of mud or incrustation will be impossible; the heat canbe increased to more than 300 centigrade; and this fluid will not freezeeven at 40 centigrade; consequently an apparatus filled with thisimproved fluid is applicable to rooms which are not continually heated,such as churches, railway-carriages, &c.

The newer method or high-pressure apparatus, which by recentimprovements has been divided in two classes, the medium and weather,and the short duration of the different parts of the apparatus; besides,the great vehement circulation of the overheated water in the apparatusand pipes subjects them to a perpetual shaking, whereby the joints areloosened, and costly repairs continually required.

Several other fluids have been tried, such as mineral oils. &c., which,in practice, have shown the difficulty of a gradual decomposition;besides, the combustibility of heated mineral oils renders their usemost dangerous. Glycerine, too, has been used, pure or combined withwater; but the same is subject to a slow decomposition, and has,besides, the peculiarity to boil by shocks.

The new and improved fluid inventedby us consists in the employment ofglycerine in which is dissolved chloride of calcium, or similarhygroscopic salts dissoluble in glycerine, so that the specific gravityof glycerine, which is 1.26, increases in the mixture to 1.40 to 1.45.The point of ebullition of this fluid is in ratio to the greater orsmaller addition of salt, 330 to 300 centigrade. No change of heat willinfluence this improved fluid, even though it were used in open vessels;the humidity taken from the air would instantly be again evaporated.

This fluid may therefore be employed in We I ry system of heating, aswell as for cooking apparatus and different baths, and recommends itselfparticularly for baking-ovens, varnish-stoves, and railway-carriages,&c. It is entirely free from all those objections to water, mineraloils, or glycerine, pure or mixed with water. It is not subject tofreezing, even in the greatest cold. It isincombustible, does notcorrode any metal, and no pressure of more than one atmosphere will actin the pipes when they transmit a temperature of 340 centigrade. Thisglycerin'e composition is of particular advantage in heating bakersovens, there being no risk of explosion, and the apparatus will have alonger duration. In cooking-stoves the use of this composition isequally commendable, because the meats can never be burned; no pressuretakes place in the apparatus, which is therefore less costly. Theheating apparatus not being necessarily

